GRAVITY INDUCED NEAR-SURFACE STRESSES IN LONG-SYMMETRICAL RIDGE-VALLEY SYSTEMS

Patterns of near-surface gravity and tectonically-induced stresses within ridge-valley systems greatly illuminate our understanding of important geodynamic processes as well as design of experiments to elucidate them. This paper presents analytical results derived for a number of geometrical configurations and range of mechanical properties of a ridge-valley system using the elastic solution of McTigue and Mei. The study reveals (i) the presence of non-zero compressive stresses near the ridge crests, which decrease with increasing Poisson's ratio (mu) and reduce to zero at ridge crests for mu = 0.5 and that (ii) the central tensional regime characterizing a valley becomes narrower due to the presence of two ridges, and decreases with increasing mu, becoming compressive at depth. For all geometrical parameters considered, all components of stress show concentration at the outer flanks of the ridges and increase with depth approaching a standard state of stress.